Ran IMWI last year and ran a 3:29 marathon. Fresh I feel like I would have been somewhere around the 3:05 area.

This year due to new baby and some injuries earlier in the year year, my training miles have been low.My logs are up to date

Last weekend I did a three day race series on trails in which I ran a 6.2 night run Friday night (8:30 per mile), a 15.5 mile Saturday morning (8:59 per mile) and a 50k on Sunday in 5:18. It was down pouring rain the ENTIRE race on Sunday which made the course very slow. I feel I would have been 5 to 10 minutes faster if it were not for the rain and mud. I felt good through about 20 miles of the 50k but the last 11 were a real challenge. My breathing was fine the entire race, but legs were dead.....The course I ran was very hilly in comparison to the 50 miler I am planning on running. The 50 miler is on very smooth trails/crushed gravel and from what I hear is very flat.

I really have no clue how to pace myself and I don't feel like my 50k race really helps me much considering I ran a 10k and a 25k in the days leading up to it. Any help would be appreciated

Your first goal should be to finish. Learn from the race. If the worst thing that happens is you feel like you could have run the whole thing a minute-per-mile faster, you've had a good day. Then do another.

Your pace should feel very easy, comfortable. Legs get too dead and tired and heavy after 20? You've still got more than 1/2 the race to do! It should feel comfortable for the first 50k, at least. Pick it up after 40 if you think you can.

I'm sure others have better advice, but I think you're trying to translate fast road times and IM running to ultras and it's a different game.

Your first goal should be to finish. Learn from the race. If the worst thing that happens is you feel like you could have run the whole thing a minute-per-mile faster, you've had a good day. Then do another.

Your pace should feel very easy, comfortable. Legs get too dead and tired and heavy after 20? You've still got more than 1/2 the race to do! It should feel comfortable for the first 50k, at least. Pick it up after 40 if you think you can.

I'm sure others have better advice, but I think you're trying to translate fast road times and IM running to ultras and it's a different game.

bingo.

road marathon to ironmarathon, obviously different ballgame! road to trails, even bigger gap. throw in another 19 miles ontop of a 50K and now nutrition becomes a MAJOR player as well. Comets first sentence is golden.

"throw in another 19 miles on top of a 50K and now nutrition becomes a MAJOR player as well Comets first sentence is golden."

I would be most worried about nutrition. If your pace gets too close to "redlining" too early in the race you won't be able to process nutrition which for a 50 miler is pretty necessary. A few gels might work for a 50k, but most people would need more for a 50 miler.

Also, although this might not apply to your course, the course markings on trail runs can be a bit confusing if you're not accustomed to them. You want to be sure you aren't going so fast that you miss a turn. Extra mileage no es bueno in an ultra.

U sound fast. But seems to me that u simply hit the wall at 20 miles. Which is where everyone hits the wall if they don't pace correctly. I am quite a bit slower than u but an idea would be to try to find a workout pace where u can go 4-6 hours and a nutrition strategy that allows u to feel really good. I got the point in my training where I could go for 6 hours and finish and feel, I kid u not, at 90 percent. Like I had ENERGY. I felt I could go another 6 hours. Fwiw I relied on boost and Gatorade exclusively. I credit this training to allowing me to finish a recent 100 miler in 33 hours which was more than 5 times the time spent in my longest training run.

Like I said, I am a bit slower, but I think the point is that where in a marathon u better have gas in the tank at 20 miles, in an 50 miler u best be feeling pretty strong at 60k.